


Alex's Morning Surprise

by KalexandraDanvers



Category: Supergirl (TV 2015)
Genre: Alien Biology, Anal, Breeding, Caught, Come Swallowing, Consensual Underage Sex, F/F, Impregnation, Kalex, Knotting, Porn, Pseudo-Incest, Shameless Smut, Short & Sweet, Sister Complex, Sister/Sister Incest, Smut, Tentacle Sex, Tentacles, Triple Penetration
Language: English
Status: Completed
Published: 2019-11-10
Updated: 2019-11-10
Packaged: 2021-01-23 03:44:33
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,581
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21313648
Author URL: https://archiveofourown.org/users/KalexandraDanvers/pseuds/KalexandraDanvers
Summary: Alex and Kara make some new discoveries and have a rather...interesting morning.
Relationships: Alex Danvers/Kara Danvers
Comments: 29
Kudos: 290





	Alex's Morning Surprise

Alex and Kara were cuddling in bed, like every morning. Unlike every morning Alex woke up to being humped by her little sister. This wasn't necessarily unusual, sometimes Kara would grind and hump her while she slept or early in the morning. Kara was grinding heavily against her ass, Alex could feel how wet her little sister was. She was always so horny. They'd had sex at least five times a day every day this week, and they'd went to school almost every day as well (hell they'd fucked at school a few times too) plus their parents had been home every day not making hiding their relationship from them easy. 

Alex's mind was drawn back to the increasingly vigorous and not-so-dry humping. Kara let a deep moan and picked up pace just a bit more. Alex felt it when Kara came, she soaked through both her and Alex's pants. Alex rubbed her ass into the sticky wetness, her and Kara both moaned and grunted as they grinding against each other. Just as Alex was about to reach her climax Kara woke up. 

"Wha..? Alex? Oh!" 

"Good morning to you too." Alex giggled. She was a bit disappointed about her unreached orgasm but it probably wouldn't take much to get Kara to finish the job. In fact Alex was going to get work on that now, she quickly started pulling/kicking off her pants.

"Was I-"

"Humping me? Yes." Alex rolled over almost too quick for even Kara to respond and then equally quickly pinned Kara to the mattress. "I want to cum. I want you to make me cum." Alex moved ever upwards clearly indicating what she was going to do and wanted Kara to do. Kara slid her big sisters panties to the side and started licking her dripping wet pussy. "Fuuuh yes! Good girl..." Alex grabbed hold of the headboard and started grinding herself against Kara's face. "Almost...almost...almost the-" Alex covered her mouth as she cried out, she finally came, the wait was more than worth it. Alex rubbed her now pouring pussy all over Kara's pretty face.

"That's a good look on you." Alex leaned down and sloppily kissed her little sister, she shoved her tongue down into Kara's mouth and tastes herself, next she planted several little kisses all over Kara's cum covered face. "Fuck I haven't felt this horny in a while..." Alex attacked Kara's neck with kisses and bites that would never leave a lasting mark. Alex shoved her hand into Kara's and panties, she placed her index finger directly over Kara's clit and started slowly rubbing it. 

"Ohhhhh...." Kara moaned long and soft, her breath was hot against Alex's neck. Kara returned Alex's previous affections and kissed, sucked and bit her exposed neck. Alex wrapped her free hand around Kara's head and urged her to keep going. Meanwhile she'd slipped her index and middle fingers inside of Kara's eager pussy, as soon as her fingertips had pushed inside Kara cried out. Alex, without removing her fingers or stopping them from penetrating further, nervously glanced behind her shoulder. She seriously hoped her parents didn't hear that. After a few moments Alex turned back to face her lover, she passionately kissed her and pulled her fingers out of Kara's cunt. 

Alex swung Kara's leg over one of her own and immediately started scissoring her. Their wet pussies made the experience all the easier and more pleasurable. Alex sped up a bit, careful not to get too loud lest they alert their parents to what was going on. Alex reached out and choked Kara with her now free right hand. It didn't do much for Kara but she knew Alex liked it, she also knew Alex loved being choked, something Kara wasn't too fond of as she was afraid of hurting Alex, or worse. Still she tried to give Alex what she wanted from time to time. Kara reached and and grasped Alex's neck and applied pressure very lightly, enough for Alex to feel it but not for it to hurt too much, a little bit of pain was kind of the point. 

Alex grinned at Kara and started thrusting more furiously, soon both women were on the precipice of their orgasms. "Harder!" Alex commanded. Kara knew what she meant and applied a bit more pressure to her neck. Alex growled her approval and ground into her pussy roughly as she climaxed. "Fucking fuh-yes!" Alex groaned through gritted teeth. "Fucking yes Kara! God i love fucking you! Gah! I fucking love you~" Alex half-cried out the last bit. She never stopped grinding against Kara and had cum again. 

Sweaty and out of breath both ladies leaned back and relaxed their bodies. "I love you too Lexie." Kara panted. Alex smiled and let herself fall backwards onto the bed. "God that was great..." She laughed. "C'mere princess." Alex motioned with her finger for Kara to come closer. Alex lifted her head of the bed and pressed a kiss to Kara's soft, supple lips. 

Kara smiled down at Alex and leaned in for another kiss, which Alex happily gave her. Kara laid down in bed next to Alex and wrapped her up tightly in her arms, and snaked their legs together. Kara pressed herself as hard as she could against Alex as she could without hurting her. Kara planted several losses along Alex's neck and jaw. "I love you." *kiss* "I love you." *kiss* "I love you!" *kiss* "Rao I fucking love you!" 

Alex didn't mind the clinginess too much, she was used to by now, Kara had been just as clingy as she was horny lately. Alex didn't quite know exactly what was going on, but she'd heard her parents once mention something about Kryptonians going into heat every so often and had been wondering if that's what this was. If so Alex figured it'd eventually run it's course and things would go back to normal, and until then she'd do what she could to help Kara, and herself of course, as the sex was fucking great. (though to be fair though Alex had only ever had sex with Kara so she had no other frame of reference)

Before long the two girls had fallen asleep, both were still naked and were barely covered by blankets. They'd slept soundly for a few hours before Alex was woken up by an odd feeling, like something slimy was creeping up her leg. Alex blinked her eyes open, her vision was kind of blurry but she could still make out a long, twisting, something (Alex genuinely could not identify what it was) snaking it's way up her left leg. Alex rubbed her eyes and when she opened them again she almost screamed. At first she'd thought it was an actual snake, but quickly realized this wasn't case, whatever it was, it really wet and slimy and oddly warm too. The thing started to move again and Alex jerked up in surprise.

Kara jolted awake and cried out in pain. "Ow!" 

Alex looked back at her sister then down at the slimy thing, then back to her sister and then back down at the thing. Alex curiously stared at the slimy thing and pulled her leg forward. "Ah! Ow!" Kara cried out again. Well that confirmed that. "Kara." Alex said very (almost too) calmly. 

"Y-yeah?"

"What is that." Alex said, her voice still level and eerily calm. 

"I-I don't know..."

"You don't know?"

"N-no."

"Hmm. Well it's attached to you."

"I-I uh, can see that..." 

"Oh you can, can you? Well that's good, that's great. Hey Kara?" Alex's voice broke a little that time.

"Yeah?" Kara answered nervously.

"What the actual fuck is it!" Alex yelled. She'd momentarily forgotten that their parents were home. Alex paled and spun her head towards the door. It was quiet, very, very quiet, Alex could hear her own heart thumping in her chest. After about 45 seconds it was apparent no-one was coming. Alex turned back to face Kara. Before either of them could talk the thing started to move again ever upwards, Alex got jumpy again and jerked her leg causing Kara to yet again cry out in pain. 

"That really hurts Alex!" 

"I'm sorry! But there's a...I don't even know...wait a minute..." Alex looked at the thing, really looked at it, and after a few seconds figured out what it was. "Kara why is there a fucking tentacle wrapped around my leg." Alex's voice was eerily calm again. 

"I-"

"Kara."

"Y- yeah?" 

"Why is it moving towards my pussy." 

Kara flinched. "I-"

Alex inhaled sharply and closed her eyes. "I swear to Rao Kara if you tell me you don't know one more fucking time I'm going to yank my leg as hard I can." 

"I do-"

"Kara!" Alex snapped. 

"Okay! Maybe!"

"Maybe what!?" 

"I might have an idea of um what's happening..."

"Would you mind sharing it!?" 

"Well, one time some of the kids in the school talked about how we- Kryptonians, used to um, have uh, these special well...um...tentacles for uh...for sex. Well more specifically for re-um, r-reproduction." Kara's face was on fire, she looked away from Alex and down at her crotch. "Hey uh Alex..."

"Yeah?" 

"So um, there uh, theres- well..."

"What?"

"There's uh, there's three more." 

"I'm sorry what?" Sure enough Alex felt three more tentacles start to wrap themselves around her leg, wriggling and writhing about. Soon they'd joined the first tentacle and all four made their way up Alex's thighs. Their destination was obvious. Alex managed not to freak out and jump this time, instead she froze up as the tentacles reached her inner thigh. Without hesitation one of the tentacles slipped itself inside of Alex's pussy and another was obviously making it's way to her asshole, which was then promptly penetrated as well. 

"I'm sorry!" Kara said. She tried pulling back but nothing happened. "I didn't mean to...I'm not trying to...y-you know..." 

Alex was still frozen from shock and didn't respond. The tentacles inside of her began exploring their new surroundings, moving further and deeper inside of Alex. Alex moaned, she couldn't help it, this was a new and really weird feeling. Kara tried getting up only to cry out again, despite this she thought to try it again and this time fell on top of Alex. 

"Hey! Easy!" Alex grumbled. At least she wasn't frozen anymore...

"Sorry! Here I'll-"

"Don't dummy, you'll only hurt yourself again." Alex scolded. She pulled Kara back down on top of her. 

"It's better than hurting you." Kara said, she tried getting back up but Alex pulled her down again.

"You're not hurting me." Alex felt it as the other two tentacles wrapped themselves around the one in her vagina and also entered. "I-ah! It doesn't hurt...it kinda..." Alex was going to say feels good but didn't want to. This was too weird. They should stop this...right? The tentacles all sped up, each moving at slightly different speeds, the sudden burst of pleasure made it hard for Alex to think. Alex looked up at Kara, her sister gasped and started moaning too. Apparently, and kind of obviously Kara could feel everything the tentacles were doing. Her tentacles? The? Alex didn't know how to properly address them. 

"Alex! I-I'm sor-sorry! I-" Kara was breathing hard, her voice was kind of shaky and she looked to be upset. 

"It's okay Kar." Alex panted. "I know." Alex squeezed her eyes shut. Why did this have to feel so fucking good? 

Kara started thrusting her hips into the source of her pleasure, increasing her own as well as Alex's. Neither had noticed the fifth tentacle protrude. They'd both closed their eyes. Kara did however eventually feel it, she opened her eyes and seen it make it's way, through the air, towards Alex's face. "Alex there's ano-" Too late. The fifth tentacle had quickly made it's way into Alex's open mouth, without hesitation it set about fucking her throat. Alex gagged and coughed in surprise but there wasn't much she could do. The sensations were overwhelming her and she felt like she couldn't move, which Alex realized was probably intentional on the tentacles part. They were for reproducing after all, they probably-hell definitely, did something to make their mate feel immense, overwhelming pleasure to further increase the chances of a successful impregnation. Alex was very aware of this, and still couldn't help but want it. She wanted Kara to keep going, to cum in her, to fuck her pregnant. She wanted it sooo fucking badly. Her whole body felt like it was on fire with pleasure, it was almost painful. She desperately wanted Kara to fill her up. She really shouldn't but she did.

Alex couldn't take this feeling of being so close to the edge anymore and started thrusting back. The tentacles seemed to respond to this and started moving way faster, as fast as they possibly could. Kara looked like she was about to pass out. Alex hadn't thought about how this must fell for her. If it felt this good for Alex it had to be just as good or better for Kara. Soon both women reached their orgasms. Cum practically exploded from all of Kara's tentacles, filling Alex's ass, mouth, and pussy. Alex had never felt so full before. Her stomach looked a little bit bigger after all that. She could feel the tentacles retreat from her mouth and ass and join those in her pussy. They then formed a knot around the entrance to Alex's womb to prevent any more cum from leaking out. Speaking of there was now a decent pool of cum and sweat around them, these sheets were definitely ruined, maybe the mattress too...

"Al-Alex...I..." Kara actually did pass out this time and fell on top of Alex. Alex herself was in a sort of state of shock again. All her holes had been filled to the brim, her stomach had been too, and she'd just had the most intense orgasm of her life. If not for the tentacle that had been throat fucking her she would've probably shredded her vocal chords from screaming. Alex felt herself start to feel really light headed and dizzy. There was another feeling to one impossible to explain but one she could fell all the same, a strange sense of knowing. Yes. Alex could feel that she was definitely...No. No. No. Nope. Nuh-uh. It's fine. Totally, totally fine. Everything was going to be fine. It was all going to be fine. 

A few weeks later

Things were not fine. Very far from being fine. Alex was pacing around the bathroom having a mini panic attack. Fuck. Fuuuuck. Fuck! Alex slumped against the wall and let herself slide down it. Rao damn it...

"Alex?" Kara asked, knocking on the bathroom door. 

"You okay?" 

"Kara? I um..." Alex trailed off she didn't know what to say. 

"Alex?" 

No reply. "Alex I'm coming in." Alex flinched at those words. 

Kara burst in the bathroom and quickly rushed over to Alex who was sitting in the corner of the room with her head in her knees. "Alex? What's wrong?"

"I...we...here." Alex handed Kara an object she instantly recognized was a pregnancy test. It was positive. 

"Oh."

Alex didn't say anything. 

"Alex are-"

"Yeah. I'm pregnant..." Neither of the two girls had noticed Eliza standing in the doorway. 

"You're WHAT!?"

...

**Author's Note:**

> Just a short little smutty piece I've been working on here and there in my free time. I hope you all enjoy and thanks for reading! 
> 
> Also, I probably won't be adding another chapter to this 'cos im evil. 😈


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